Tube flattening and bending machine

ABSTRACT

A machine for flattening portions of a straight length of tubing and for bending the tubing into a zigzag shape. Movable outboard stations are mounted by rollers on a rail extending to each side of an immovable central station. Associated with each station is an anvil and hammer assembly to hold, to flatten and to grip a portion of the tubing. A hydraulic cylinder is mounted on alternate outboard stations to move the anvil and hammer assembly in an upwardly direction from the rail, thereby bending the tubing into a zigzag shape.

United States Patent [72] Inventor Dan G.Williamson 2,661,787 12/1953Eidal 72/383 llndependence,Mo. 2,702,576 2/1955 Eidal 72/383 [21] 842312Primary Examiner-Wiliam S.Lawson [22] Filed July 16,1969 A S f d K S fId 45 Patented Dec. 21, 1971 0 [73] Assignee Butler ManufacturingCompany Kansas ABSTRACT: A machine for flattening portions of a straightlength of tubing and for bending the tubing into a zigzag [54] TUBEFLATTENING AND BENDING MACHINE shape. Moyable outboard stations aremounted by rollers on a rail extending to each slde of an immovablecentral station. 12 Claims, 5 Drawing Figs.

Associated with each station is an anvil and hammer assembly U-S-Cl .tto hold to flatten and to grip a portion of the tubing, A 16 hydrauliccylinder is mounted on alternate outboard stations to move the any andhammer assembly in an upwardly Field of Search 12 6 1 6; direction fromthe rail, thereby bending the tubing into a zigzag shape.

[56] References Cited UNITED STATES PATENTS 2,086,736 7/1937 Palmer72/385 '1 0 1 1 /a T 7.9 14k? 1 wil at int w? Him #5 m/ I I 4 7 .mn as,/6 l 27 PATENTED UEBZI IE7! SHEET 3 BF 3 m W W W a H w I TUBE FLATTENINGAND BENDING MACHINE BACKGROUND OF THE INVENTION The art of bending astraight length of tubing into a zigzag shape, known in trade as a web,has long practiced. One useful application of this product isconstruction of a truss structure such as a bar joist which is formed byrigidly attaching straight members known as chords to the apices of thezigzag web member.

Many machines have been devised to bend tubing into a zigzag shape. Tomy knowledge, these bending machines can be classified into one of threebroad categories.

Perhaps the oldest type of bending machine is one which makes successivebends to a straight length of tubing as it is fed to the bendingapparatus of the machine. For high-production requirements of identicalweb members, this method of bending is much too slow.

A second type of bending machine has a plurality of bending deviceswhich accommodates the entire straight length of tubing. Successivebends, beginning at one end of the tubing, are made one at a time bymechanically drawing successive bending devices toward the opposite endof the tubing which is held stationary by the machine. Likewise, thismethod of bending is slow.

The final type of bending machine is similar to the previous type exceptall bends are made simultaneously. Although much faster in production,this machine is physically limited by the great speed of the end'bendingdevice traveling toward the stationary holding device at the oppositeend.

Of the tube-bending machines of which I am presently aware, all functionto bend tubing in such a manner that the resulting apices of the zigzagweb can be described either as a sharp kink caused by collapsing thewall of the tubing, or as a smoothly rounded bend. In either case,however, the apices have an unsuitable surface on which to affix chordsshould the zigzag web be used for construction of a bar joist or similarstructure.

SUMMARY OF THE INVENTION One of the primary objects of the presentinvention is to provide a tube-bending machine operable to form a zigzagweb member having flattened portions of tubing at its apices, therebyproviding a suitable surface on which other members can be affixed. Anadditional object is to provide a machine in which the contour andconfiguration of the flattened portions of tubing can easily be varied.

Another object of the invention is to provide a tube-bending machinewhich accommodates the entire length of a straight piece of tubing andin which, during the bending operation, the ends of the tubing aredisplaced toward the center of the length of tubing rather than one endof the tubing being moved toward the opposite, stationary end of thetubing. This feature greatly reduces the speed at which machine membersholding the ends of the tubing must travel, and thus yielding aprominent safety advantage as well as decreasing wear on moving members.Likewise, web members of greater length than those formed by previousmachines can now be formed.

Another object of the invention is to provide a tubebending machine inwhich the number-of bends in the zigzag web member can be easilyincreased or decreased.

Still another object of the invention is to provide a tubebendingmachine in which the height of the zigzag web member to be formed can beeasily adjusted and changed.

A further object of the invention is to provide a tube-bending machinewhich is highly reliable and safe for high-speed production of zigzagmembers and which is economical to manufacture, maintain and operate.

Other and further objects of the invention will appear in the course ofthe following description thereof.

DETAILED DESCRIPTION In the drawings, which form a part of the instantspecification and are to be read in conjunction therewith, and in whichlike reference numerals indicate like parts in the various views:

FIG. l is a front elevational view of the components of a tubeflattening and bending machine constructed in accordance with apreferred embodiment of the invention, the movable components-positionedto receive a straight length of tubing and the break lines indicatinginterrupted length;

FIG. 2 is a front elevational view of the machine of FIG. 1 in thecondition it is in after having performed its flattening and bendingfunctions upon the tubing;

FIG. 3 is a rear elevational view of the machine in the FIG. 2configuration;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3 in thedirection of the arrows; and

FIG. 5 is a sectional view taken along line 5-5 of FIG. 2 in thedirection of the arrows.

Referring to the drawings, the basic support structure of the wholemachine comprises a horizontal rail 7 which is shown supported by afloor anchored column 8. The rail 7 is of sufficient length toaccommodate a straight length of tubing 9 (shown in broken lines) fromwhich a zigzag web member is to be formed. Rail 7 is a box-bearnlikestructure, having generally the appearance in cross section of the Romannumeral II, as best seen in FIGS. 4 and 5 The rail may be made as longas required. Although a single column 8 is shown for purposes ofillustration, additional columns 8 normally are provided at appropriateintervals along the length of rail 7 for necessary support.

Referring particularly to FIG. I, an immovable central station islocated approximately midway along the length dimension of rail 7.Station 10 comprises an upper anvil and hammer assembly, generallydesignated as numeral 11 and an inverted L-shaped base 12 which isrigidly affixed on the top and front faces of rail 7.

The anvil and hammer assembly is carried by a support member 13 which,in the preferred embodiment, is an e|on gated boxlike structure whichextends above the top rail 7 and is located forwardly of the front sidethereof. Support 13 is rigidly attached to the top and front faces ofbase 12 and has the general configuration shown in FIG. 5, which, aswill be seen, shows a movable station rather than a fixed station.

The anvil of anvil and hammer assembly 11 is indicated at 14 It isremovably mounted (by bolts or other conventional fasteners) on thefront face of support member 13 slightly above rail 7, and comprises ablock with a flat upper anvil surface Ma.

Also mounted on the front face of support member l3 but at its uppermostend is a double-acting hydraulic cylinder I5 into two internal chambers.Connection 16 provided access to chamber behind the internal piston andconnection 17 provides access to the chamber in front of the internalpiston. The piston is fitted with an extrusion 18, which projectsexternally from hydraulic cylinder 15 and downwardly toward anvil 14.

A hammer I9 is removably mounted on the end of the extension l%. Theseparated distance between the tube-engaging surface of anvil 14 ispreferably just slightly greater than the outside diameter of the tubingto be handled by the machine. In the preferred device, the working endof the hammer is shaped much like the blade of a screwdriver with a flatlower end. Attached to and extending rearwardly from the opposite sidefaces of support member 13 are support bars 20. As can best be seen inFIG. 3, a cross member 21 is attached to and extends between and issupported by the ends of bars 20. A horizontal pivot pin 22 is connectedto the crossmember 21 and the axis of pin 22 coincides with thehorizontal centerline running from front to rear of the tube-engagingsurface 141 of its associated anvil I4.

Disposed on rail 7 and spaced at intervals therealong outboard stations25 which are similar in basic structure to station ill) but differtherefrom in that they are supported for movement along the rail. Theanvil and the hammer assemblies 11 associated with stations 25 havemembers 13 through 22 identically corresponding to those memberspreviously discussed with respect to station and therefore aredesignated by like reference numerals.

The distinguishing structural difference between stations 25 and station10 is the manner of connecting the anvil and hammer assemblies 11 torail 7.

As best viewed in H6. 5, the assembly support member 13 of each station25 is attached to an inverted U-shaped frame 26 disposed across rail 7and having the side legs 26a, 26a and bight 26b. A plurality of guiderollers 27 are connected to the frame 26 and engage the top, side andbottom surfaces of each face of rail 7. The rollers permit the movablestation to ride freely along the rail and at the same time stabilize thestation in a fixed orientation with respect to the long axis of therail.

Disposed on rail 7 on each side of the stationary central station 10between station 10 and moveable stations 25 are second movable outboardstations 28, which are similar in several aspects to stations 25 andstation 10. The anvil and hammer assemblies associated with stations 28have members 14 through 22 corresponding to those members previouslydiscussed with respect to stations 25 and station 10 except that theentire anvil and hammer assembly 1 1 is rotated 180 about a centerlinerunning from front to rear and bisecting the distance between thetube-engaging surface of anvil l4 and hammer 19. Being so positioned,hydraulic cylinder is disposed on the lowermost end and anvil 14 isdisposed on the uppermost end of support member 13 as viewed in FIG. 1.

Rather than being rigidly attached to a frame 26 as in station 25,support member 13 is supported for up and down movement along a verticalbeam 29 by a plurality of rollers 30, best viewed in FIG. 4. Beam 30 isrigidly attached to the inverted U-shaped frame 26 which has associatedrail-engaging rollers 27, as earlier described with respect to stations25. The beam 30 has vertically running flanges with which the rollers 30cooperate.

Mounted on the lower portion of the front face of beam 30 and extendinginwardly through the hollow support member 13 is an elongatedouble-acting hydraulic cylinder 31. A movable internal piston (notshown) divides hydraulic cylinder 31 into two internal chambers.Connection 32 provides access to the chamber below the internal pistonand connection 33 provided access to the chamber in front of theinternal piston. Attached to the piston in an extension 34 whichprojects upwardly from the cylinder to connect to the uppermost endofsupport member 13 as at 34a.

The upright beam 29 has a lower portion 29a which parallels cylinder 31and to which the cylinder is connected. Located on the rear face of suchlower portion is a roller 35 which engages a horizontal bar or track 36which is attached to columns 8 beneath rail 7. As can best be seen inFIG. 3, station 10 is connected to stations 28, and the latter tostations by connecting links which extend between the respectivestations and have their ends pivoted to the pins 22 on the back side ofeach station. As earlier mentioned, each station has a pivot pin 22extending rearwardly from crossmember 21 of the anvil and hammerassembly 11.

As will subsequently be seen, the distance to which stations mayapproach one another during inward travel toward the midpoint of therail, which is the location of the stationary central station 10, iscontrolled by limit stops attached to the stations. These are preferablyon the form of threaded studs 38, one for each station, which extend toone side of the station in position to engage the next inboard sectionwhen the distance between them has closed sufficiently. Locknuts 39 areprovided on the studs. The limit distance between stations can bechanged by threading the studs in or out, as necessary.

The tube flattening and. bending machine is utilized to form a zigzagweb member in the manner to be described.

With the stations in the condition illustrated in FIG. 1, a straightlength of tubing 9 is placed between the anvils 14 and hammers 19 ofstations 10, 25, and 28, the latter having, of course, first beenpositioned in the spaced away position with respect to the anvils. To dothis, pressurized fluid is introduced onto the chamber behind theinternal piston of hydraulic cylinder 15 through connection 17 by asuitable means, such as a conventional hydraulic pump and two-way valve(not shown), which influences connecting rod 18 and hammer 19 away fromanvil 14. When the tube is in place, the flow is reversed to impel thehammer toward the anvils. This action collapses tubing wall and flattensa limited portion of the tubing at each station to the contour anddimensions of the tubeengaging surface of hammer 19.

Although it is not essential to the flattening operation, it isdesirable that the connections 16 and 17 of each station be respectivelyconnected in series by flexible hoses to common lines of a conventionaltwo-way hydraulic circuit. This allows substantially simultaneouslyflattening of the portions of tubing between anvil 14 and hammer 19 ofeach station.

Once flattening is completed, and while maintaining flattening pressure,pressurized fluid is introduced into the chamber behind the internalpiston of the hydraulic cylinders 31 through connections 32 through atwo-way hydraulic circuit (not shown) independent of the flatteninghydraulic circuit. This causes the piston extensions 34 to move in anupwardly direction and, since the extensions carry the anvil and hammerassemblies 11, of station 28, the anvil and hammer assemblies moveupwardly on rollers 29 along beam 30. Although it is not essential tothe bending operation, it is desirable that the connection 32 of eachstation 28 be connected in series or in parallel by flexible hoses tothe two-way hydraulic circuit. This allows substantially simultaneousbending to occur and thereby increases the production speed.

Firmly held between anvil 14 and hammer 19, the flattened portion oftubing 9 also travels in an upwardly direction along beam 29 andinitiates the bending of the tubing. At the same time, the stationconnecting links 37 are displaced upwardly at station 28, causing themto pivot about pins 22, and exerting forces operating to pullneighboring stations together. Since the central station 10 is rigidlyaffixed to rail 7, all outboard stations are pulled inwardly towardstation 10 and they will continue to move until the limit stops 38 areengaged all along the line. The condition of the machine at this time isillustrated in FIGS. 2 and 3.

Pressure on the fluid in hydraulic cylinders 15 is now released, andpressurized fluid is introduced into the chamber in front of theinternal piston of hydraulic cylinder 15 through connection 17, whichforces the fluid behind the internal piston out through connection 16and also forces connecting rod 18 and hammer 19 to return to theiroriginal position. At this point, the anvils 14 and hammers 19 no longergrip the tubing and the zigzag member can be manually removed from themachine.

Next, the pressure on the fluid in hydraulic cylinders 31 is releasedand pressurized fluid is introduced into the chamber in front of theinternal piston of hydraulic cylinder 31 through connection 33, whichforces the fluid behind the internal piston out through connection 32and also forces anvil and hammer assembly 11 downwardly along beam 29 toits original position as viewed in FIG. 1.

The number of bends in zigzag web members subsequently to be formed canbe easily increased or decreased. This is accomplished by adding ordeleting additional outboard stations at either end of rail 7. Extraoutboard stations can be removed from rail 7 simply by rolling saidstations off the end of the rail. Alternatively, extra stations can bestored at the ends of rail 7 if these areas of the rail are not neededto form a zigzag web member. All connections needed to add an outboardstation are exceedingly simple. A station connecting arm 37 and suitablehose to the hydraulic cylinders is all that is required.

Likewise, the height and angle of the zigzag web member to be formed canbe easily adjusted and changed. This is accomplished by looseninglocking nuts 24 on each station, adjusting bolts 23 to a desired lengthand then retightening locking nuts 24, or by substituting link members37 of different length, or both.

From the foregoing, it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

Since many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A tube-bending machine operable to form a straight length of tubinginto a ZigZag web member having flattened sections of tubing at itsapices; said machine comprising:

a normally fixed central station;

a rail member extending on both sides of said central station, said railmember of sufficient length to accommodate said straight length oftubing from which said web member is to be formed;

aplurality of movable outboard stations mounted on said rail member withat least one on each side of said central station;

a tube flattening and gripping assembly associated with each saidstation, each of said assemblies having tube-engaging surfaces andoperable to flatten and to grip a section of said tubing;

first power means for operating said assemblies to flatten and to grip asection of said tubing;

bending means associated with at least one movable outboard station oneach side of said central station, said bending means operable to movesaid flattening and gripping assemblies of said one movable outboardstation on each side of said central station in a directionsubstantially perpendicular to the lengthwise direction of said railmember;

second power means for operating said bending means of said one movableoutboard station on each side of said central station; and

link means for connecting successive stations, said link means operableto cause said movable outboard stations to move toward saidcentralstation as said second power means operates said bending means.

2. The machine as in claim 1, wherein a plurality of said movableoutboard stations are alternately disposed on said rail members awayfrom said central station such that an outboard station having bendingmeans is followed by an outboard station having no bending means and anoutboard station having no bending means is followed by an outboardstation having bending means.

3. The machine as in claim 1, wherein said movable outboard stations aremounted on said rail members by rollers to permit movement of saidoutboard stations along the lengthwise direction of said rail members.

4. The machine as in claim 1, wherein each'of said assemblies includes:

an anvil having a tube flattening and gripping surface;

a hydraulic cylinder;

at reciprocable piston associated with said hydraulic cylinder; and

a hammer opposed to said anvil having a tube flattening and grippingsurface connected to said piston of said hydraulic cylinder.

5. The machine as in claim 4, wherein said tube flattening and grippingsurface of said anvil conforms to said tube flattening and grippingsurface of said hammer to impart the contour and dimensions of thelatter surface to the flattened sec tion of said tubing when saidactivating means operates said assembly.

6. The machine as in claim 4, said anvil and hammer removably mounted onsaid assembly.

7. The machine as in claim I, each of said bending means including ahydraulic cylinder and a piston associated with said hydraulic cylinderconnected to said assembly.

8. The machine as in claim 1, said first means capable of substantiallysimultaneously operating said assemblies to flatten and to grip sectionsof said tubing.

9. The machine as in claim 1, said second power means capable ofsubstantially simultaneously operating said bending means of saidmovable outboard stations.

it). The machine as in claim 1, said link means for connectingsuccessive stations including link member extending between saidsuccessive stations one end of said member pivotally connected to one ofsaid stations and the other end of said member pivotally connected tothe other of said stations.

Ill. The machine as in claim 1, wherein stop means prevent successivestations from moving closer to each other than a preselected distancewhen said second power means operates said bending means.

12. The machine as in claim 11, said stop means including adjustablebolt means, at least one of which is connected to each of said stations,said bolt means having a station engaging surface to prevent successivestations from moving closer to each other than a preselected distancewhen said second power means operates said bending means.

1. A tube-bending machine operable to form a straight length of tubinginto a ZigZag web member having flattened sections of tubing at itsapices; said machine comprising: a normally fixed central station; arail member extending on both sides of said central station, said railmember of sufficient length to accommodate said straight length oftubing from which said web member is to be formed; a plurality ofmovable outboard stations mounted on said rail member with at least oneon each side of said central station; a tube flattening and grippingassembly associated with each said station, each of said assemblieshaving tube-engaging surfaces and operable to flatten and to grip asection of said tubing; first power means for operating said assembliesto flatten and to grip a section of said tubing; bending meansassociated with at least one movable outboard station on each side ofsaid central station, said bending means operable to move saidflattening and gripping assemblies of said one movable outboard stationon each side of said central station in a direction substantiallyperpendicular to the lengthwise direction of said rail member; secondpower means for operating said bending means of said one movableoutboard station on each side of said central station; and link meansfor connecting successive stations, said link means operable to causesaid movable outboard stations to move toward said central station assaid second power means operates said bending means.
 2. The machine asin claim 1, wherein a plurality of said movable outboard stations arealternately disposed on said rail members away from said central stationsuch that an outboard station having bending means is followed by anoutboard station having no bending means and an outboard station havingno bending means is followed by an outboard station having bendingmeans.
 3. The machine as in claim 1, wherein said movable outboardstations are mounted on said rail members by rollers to permit movementof said outboard stations along the lengthwise direction of said railmembers.
 4. The machine as in claim 1, wherein each of said assembliesincludes: an anvil having a tube flattening and gripping surface; ahydraulic cylinder; a reciprocable piston associated with said hydrauliccylinder; and a hammer opposed to said anvil having a tube flatteningand gripping surface connected to said piston of said hydrauliccylinder.
 5. The machine as in claim 4, wherein said tube flattening andgripping surface of said anvil conforms to said tube flattening andgripping surface of said hammer to impart the contour and dimensions ofthe latter surface to the flattened section of said tubing when saidactivating means operates said assembly.
 6. The machine as in claim 4,said anvil and hammer removably mounted on said assembly.
 7. The machineas in claim 1, each of said bending means including a hydraulic cylinderand a piston associated with said hydraulic cylinder connected to saidassembly.
 8. The machine as in claim 1, said first means capable ofsubstantially simultaneously operating said assemblies to flatten and togrip sections of said tubing.
 9. The machine as in claim 1, said secondpower means capable of substantially simultaneously operating saidbending means of said movable outboard stations.
 10. The machine as inclaim 1, said link means for connecting successive stations includinglink member extending between said successive stations one end of saidmember pivotally connected to one of said stations and the other end ofsaid member pivotally connected to the other of said stations.
 11. Themachine as in claim 1, wherein stop means prevent successive stationsfrom moving closer to each other than a preselected distance when saidsecond power means operates said bending means.
 12. The machine as inclaim 11, said stop means including adjustable bolt means, at least oneof which is connected to each of said stations, said bolt means having astation engaging surface to prevent successive stations from movingcloser to each other than a preselected distance when said second powermeans operates said bending means.